Add Docker containerization stack

- Dockerfile: multi-stage Python 3.13-slim, healthcheck, uvicorn CMD
- docker-compose.yml: full stack (cAIc, SearXNG, Qdrant, RabbitMQ,
  llama-server, Ollama) with healthchecks, volumes, secrets
- .dockerignore: exclude venv, tests, .git, models, secrets
- .env.example: all variables documented with generation hints
- scripts/setup.sh: first-run scaffolding (generates .env, secrets,
  SearXNG config, directories)
- searxng-settings.yml.dist: SearXNG config template
- models/README.txt: instructions for placing .gguf files
- config.py: add HW_STATE_PATH env var (CAIC_HW_STATE_PATH)
- hardware.py: read state path from config instead of hardcoded CWD
- requirements.txt: add missing psutil and jinja2

searxng-settings.yml.dist

@@ -0,0 +1,26 @@
+# SearXNG configuration — cAIc stack
+# Secret key is injected via environment variable.
+
+search:
+  safe_search: 0
+  autocomplete: ""
+  default_lang: en
+
+server:
+  secret_key: ${SEARXNG_SECRET_KEY}
+  limiter: false
+  image_proxy: false
+  method: GET
+  port: 8080
+  bind_address: "0.0.0.0"
+
+engines:
+  - name: google
+    engine: google
+    shortcut: g
+  - name: duckduckgo
+    engine: duckduckgo
+    shortcut: ddg
+  - name: wikipedia
+    engine: wikipedia
+    shortcut: wp